1. Field of the Invention
The present invention relates generally to vehicular suspensions systems, and in particular is concerned with a compression cut-off valve for a hydraulic damper.
2. Description of the Related Art
The use of hydraulic dampers in vehicular suspension systems is widespread. In general, hydraulic dampers (e.g., shock absorbers and struts) are used with suspension springs to attenuate vibrations received from wheel assemblies and body movements. Suspension travel of each damper is limited in both the compression (jounce) and extension (rebound) directions.
When the limit of compression and/or extension travel by a damper has been reached due to undulations in a road surface combined with insufficient levels of damping force, a suspension system may "bottom out" and transmit harsh vibrations to the body. Typical suspension systems cushion against the such vibrations with elastomeric bumpers at each end of travel. Such bumpers may be formed from natural rubber, urethane foam and solid urethane. Also, hydraulic cushion methods have been used to restrict fluid flow in a hydraulic damper to increase damping as the limit of travel is reached. Such methods involve techniques which do not easily lend themselves to implementation with a twin-tube damper.
The art continues to seek improvements. It is desirable to provide a position sensitive damper having increased damping as a travel limit is reached. Specifically, it is desirable to provide such a device for known twin-tube damper designs.